What Is iPhone Firmware?

By Aaron Parson

The iPhone 5 launched with version 6 of the iOS firmware.
i Hannah Johnston/Getty Images Entertainment/Getty Images

Though the iPhone is often thought of as a pioneer smartphone, the defining feature of smartphones--the ability to install third-party apps--was actually added in iOS 2. This feature, along with the many other abilities and apps that make up the iPhone's basic operations, are collectively known as the iPhone's firmware, and come installed on every model of the device.

Firmware Definition

Many electronic devices, from modems to cell phones, contain chips with operating software written on them. Known as firmware, this software controls the device's basic operations. On an iPhone, firmware refers to the phone's operating system, iOS. The iOS operating system contains all of the iPhone's pre-installed apps, such as Mail, Safari and Notes, as well as the phone's internal programming which controls processes such as booting and connecting to the cellular network.

iPhone Firmware History

The first iPhone firmware, iOS 1, was released with the original iPhone in 2007. Subsequent firmware updates brought major changes. Released in 2008, iOS 2 added support for third-party apps via the App Store. 2009 saw iOS 3 and the ability to copy and paste text, voice control and push notifications. In 2010, Apple released iOS 4, which featured multitasking and app folders. IOS5 in 2011 added Siri, and removed the need to sync and update the phone via a computer. 2012's iOS 6 added a notification center, integrated Facebook into the system and replaced Google's Maps app with a new version designed by Apple.

iOS Cross-Compatibility

While Apple designed the first iOS firmware for the iPhone, the company has since adapted the operating system for the iPod touch and the iPad. Apple added compatibility with the iPod touch in iOS version 1.1 and with the iPad in iOS 3.2--a separate version never released for the iPhone. The iPad continued to use an alternate version of the operating system until iOS 4.2.1, which unified the iPhone and iPad firmware version numbers.

Updating iPhone Firmware

All models of iPhone feature firmware that users can update via iTunes on the computer. After connecting the iPhone to the computer, select the phone in the iTunes menu and click "Check for Updates" to update the iPhone firmware. IPhones already running iOS 5 or newer can also update directly without need of a computer through the "Software Update" option found under "General" in the Settings app. This method requires a battery at least half full and a Wi-Fi connection.

Version Warning

Information in this article applies to iTunes 10 and iOS 6. It may vary slightly or significantly with other versions.